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Rate analysis: 12.5 mm plaster 1:3, per 100 m²

Short answer

Rate of 12.5 mm plaster (1:3) wall: NPR 50,123.13 per 100 m² (NPR 501.23 per m²). For ceiling, increase labour 25% and add staging, rate becomes NPR 59,185.63 per 100 m². Lead and lift affect material cost through transport distance and vertical lift, ensuring accurate rate analysis.

Prepare the analysis of rate for 12.5 mm plastering work in 1:3 cement sand mortar per 100 square meters all complete and as per the instruction of engineer. What modification is required in the given calculation if the plaster work is for ceiling work? Also, justify why lead and lift is important for the analysis of rate work.

Rate analysis is the work of finding the cost of one unit of an item from the quantities of materials, labour and plant needed and their current rates. The rates and labour norms below are illustrative (DUDBC-style norms; use the current District Rate and norms of the project area for a real estimate): cement NPR 1,000/bag, sand NPR 3,500/m³, 20 mm aggregate NPR 4,500/m³, skilled labour NPR 1,500/day, unskilled labour NPR 1,100/day, water lump sum, contractor's overhead 15% and profit 10% on direct cost (VAT excluded).

Rate analysis: 12.5 mm plaster 1:3, wall, per 100 m²

  • Wet mortar =100×0.0125=1.2500= 100 \times 0.0125 = 1.2500 m³; dry mortar =1.27×1.2500=1.5875= 1.27 \times 1.2500 = 1.5875 m³
  • Cement =1/4×1.5875=0.3969= 1/4 \times 1.5875 = 0.3969 m³ =11.43= 11.43 bags; sand =3/4×1.5875=1.1906= 3/4 \times 1.5875 = 1.1906 m³
  • Labour (illustrative norm): mason 8 days, helper 10 days per 100 m², including mixing, curing and cleaning.
ItemQtyUnitRate (NPR)Amount (NPR)
Cement11.43bag1,000.0011,430.00
Sand1.191m³3,500.004,168.50
Skilled labour (mason)8.0day1,500.0012,000.00
Unskilled labour10.0day1,100.0011,000.00
Scaffolding, water and curing (lump)1LS1,500.001,500.00
Direct cost40,098.50
Contractor's overhead @ 15%6,014.78
Contractor's profit @ 10%4,009.85
Total (rate per 100 m²)50,123.13

Rate of 12.5 mm plaster (1:3), wall = NPR 50,123.13 per 100 m² (NPR 501.23 per m²).

Modification for ceiling plaster

The material quantity stays the same for the same thickness (in practice ceiling plaster is often only 6–10 mm thick, which reduces the mortar proportionally). The changes are:

  • Labour is increased by about 20–25%, because the mason works overhead and the output falls. Wastage from dropping mortar is also higher.
  • A scaffold or staging cost is added (plus the cost of lifting material to the floor level, if any).

Modified rate (labour +25%, staging NPR 3,000):

ItemQtyUnitRate (NPR)Amount (NPR)
Cement11.43bag1,000.0011,430.00
Sand1.191m³3,500.004,168.50
Skilled labour (mason) +25%10.0day1,500.0015,000.00
Unskilled labour +25%12.5day1,100.0013,750.00
Staging / scaffolding and water (lump)1LS3,000.003,000.00
Direct cost47,348.50
Contractor's overhead @ 15%7,102.28
Contractor's profit @ 10%4,734.85
Total (rate per 100 m²)59,185.63

Rate of ceiling plaster = NPR 59,185.63 per 100 m².

Why lead and lift matter

  • Lead is the distance from the source (quarry, market, store) to the work site. Transport cost rises with lead (it is paid per m³ or tonne per km, as per the district rate transport norms), so the same material has a different rate at different sites.
  • Lift is the vertical height through which material is raised above ground level, e.g. to upper floors. It needs extra labour or hoisting, so the cost rises with floor height.
  • Without lead and lift, the rate of the same item cannot be fixed fairly; they are added to the basic rate of the materials.

✓ Answer checked by Claude Opus 5.5 (high effort)

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